Simplified Quantification of 11C-UCB-J PET Evaluated in a Large Human Cohort

C-11-UCB-J ((R)-1-((3-(C-11-methyl-C-11)pyridin-4-yl)-methyl)-4-(3,4,5-trifluorophenyl)pyrrolidin-2-one) is a PET tracer for synaptic vesicle glycoprotein 2A, which may be a marker of synaptic density. To simplify the scan protocol, SUV ratios (SUVRs) were compared with model-based nondisplaceable binding potential (BPND) to select the optimal time window in healthy and neuropsychiatric subjects. Methods: In total, 141 scans were acquired for 90 min. Arterial blood sampling and metabolite analysis were conducted. SUVR-1 (centrum semiovale reference region) was computed for six 30-min windows and compared with 1-tissue-compartment model BPND. Simulations were performed to assess the time dependency of SUVR-1. Results: Greater correlation and less bias were observed for SUVR-1 at later time windows for all subjects. Simulations showed that the agreement between SUVR-1 and BPND is time-dependent. Conclusion: The 60- to 90-min period provided the best match between SUVR-1 and BPND (-1% +/- 7%); thus, a short scan is sufficient for accurate quantification of C-11-UCB-J-specific binding.

Automated summary

This study compared SUVR-1 with BPND to select the optimal time window in healthy and neuropsychiatric subjects, finding that SUVR-1 showed greater correlation and less bias at later time windows. The 60-90 min period provided the best match between SUVR-1 and BPND.